The TBM DiGs conference series provides a specialized technological forum discussing and exchanging knowledge related to TBM works in difficult grounds. The 4th edition will be held between the 14^th and 15^th of November 2019 at the Sheraton Denver West Hotel, in Golden, Colorado, USA.

All abstracts and manuscripts shall be submitted to the Conference staff through a web-based Document Management System (DMS) whose address is https://dms.csmspace.com: The deadline is the 3^rd of December 2018. The Conference plans to accept submittals for oral presentation and for poster presentation. For further information and topics for presentations please visit https://tbmdigs2019.org/abstracts.html. 47/18.